Mattress in a box buying guide

A full-size bed rolled into a box you can carry upstairs. Here's what to check before you click buy.

Short answer: pick the size first, check that your frame gives firm, flat support, and have a helper ready for the heavy box. Unbox it within the maker's window; once it's out, give it a few hours to air out and up to about 72 hours to reach full size.^{[1 2 3 · Oct 29, 2026]}

Before you order

• Size: use our size chart and size finder. Mattress sizes are standard, so any queen fits a queen frame.^{[4 · Oct 29, 2026]}
• Thickness: check the mattress height against your sheets' pocket depth (see sheet sizes).^{[4 · Oct 29, 2026]}
• Base: boxed mattresses need firm, solid support. One maker lists platform, panel, foundation and adjustable beds, metal frames with a foundation, and slatted frames with flat (not bowed) wood slats.^{[1 · Oct 29, 2026]} The same maker says a box spring voids its warranty.^{[1 · Oct 29, 2026]} Read your mattress's warranty for its rules.
• Trial and returns: trial lengths vary by brand. Two makers we checked offer 100 nights;^{[4 5 · Oct 29, 2026]} one starts the trial on the delivery date.^{[5 · Oct 29, 2026]}

The box

• Mattresses are compressed by industrial machines, rolled, vacuum-sealed and boxed, even models with coils.^{[1 · Oct 29, 2026]}
• One maker describes its boxes as about the size of a mini-fridge, weighing 47 to 139 lb depending on size and type.^{[1 · Oct 29, 2026]}
• Get a second person to carry it, especially on stairs, tight corners or long hallways.^{[1 · Oct 29, 2026]}

Unboxing

1. Carry the box to the bedroom before opening it. Once a mattress expands, it can't be squeezed back into the box.^{[1 · Oct 29, 2026]}
2. Unroll it on the frame, top side up, then remove the plastic.^{[1 · Oct 29, 2026]} It will look smaller than full size until the plastic is off.^{[3 · Oct 29, 2026]}
3. Let it air out and expand for 2 to 3 hours if you can, though it's usable right away.^{[3 · Oct 29, 2026]}
4. Expect up to 48 to 72 hours to reach full size. Sleeping on it during that time doesn't slow expansion.^{[2 · Oct 29, 2026]}

How long can it stay in the box?

It depends on the maker: one recommends unboxing within 3 to 4 weeks and warns longer could damage the mattress,^{[5 · Oct 29, 2026]} while another says to unbox within three months.^{[1 · Oct 29, 2026]} Check your mattress's own instructions if you're moving or renovating.

Break-in

One maker says a foam mattress takes about 2 to 3 weeks to break in, getting softer and more supportive with use.^{[2 · Oct 29, 2026]} Give it that long before you decide it's not right.

Do all boxed mattresses give off a smell when first opened, and how long does it last? Unverified. We couldn't confirm a reliable source for this yet. Airing the room out is the general advice.

Sources: 1. Casper, How do Casper mattresses ship?. 2. Tuft & Needle help, How long do I need to wait before sleeping on my new mattress?. 3. Tuft & Needle help, How do I unbox and set up my mattress?. 4. Casper, Queen size bed dimensions: size, room fit, and how it compares. 5. Tuft & Needle help, How long can my mattress stay in the box?. Checked Oct 29, 2026. Trademarks belong to their owners; figures are restated in our own words and tables, not reproduced.